This invention relates to disc drive storage devices. In particular, this invention relates to read/write heads for such disc drive storage devices.
After a disc drive is energized, it warms up and has a temperature rise. In particular, there are large temperature rises in the heads used in a disc drive. The heads include magnetic transducers deposited on slider substrates. The magnetic transducers carry read/write currents that generate heat in the heads. The temperature rise in the heads is large because the heads have a small surface area in relation to the amount of heat that is dissipated in the magnetic transducers.
In newer, higher performance disc drives, the discs have increased areal density, rotational speeds and magnetic coercivity. With increased areal density, the dimensions of the magnetic transducer, such as write tip width and gap, are made correspondingly smaller. With increased areal density and rotational speeds, the operating frequency of the magnetic transducer increases. Inductances and capacitances in a write coil need to be smaller to operate at the higher frequencies and provide fast transient response. The write coil passes through a xe2x80x9cwindowxe2x80x9d in a write core structure, and this window is made smaller to reduce inductance in the write coil. With the smaller window, there are increased power losses in the write coil, particularly where the write coil passes through the narrowed xe2x80x9cwindowxe2x80x9d of the write core structure.
The increased magnetic coercivities of newer higher areal density magnetic discs and the decreased write tip width combine to increase the need for magnetomotive force or ampere-turns in the write coil, further increasing power losses in the write coil.
This size of the magnetic transducer has scaled down at the same time that the power losses in the write coil have increased, leading to higher magnetic transducer temperatures and reliability problems.
A disc drive is needed with a magnetic transducer that can be used with high performance discs, while reducing reliability problems associated with higher power losses and high temperatures in the magnetic transducer.
A disc drive includes a disc and a read/write head accessing the disc. The head includes a thermally conductive substrate and a write coil window surrounded by a shared pole piece thermally coupled to the substrate, a central core, a write pole piece and a write gap. A bottom coil adjacent the shared pole piece has multiple turns that have bottom narrowed regions passing through the window. A top coil adjacent the write pole piece has multiple turns that have top narrowed regions passing through the window. The top turns are fewer in number and flattened relative to the bottom turns.
These and various other features as well as advantages which characterize the present invention will be apparent upon reading of the following detailed description and review of the associated drawings.